Improvement in valves for steam-engines



UNITED STATES PATENT 'QEEIoE GEORGE F. BLAKE, OF BOSTON, MASSACHSETTS.

IMPROVEMENT IN VALVES FOR STEAMV-E-NGINES.

Specification forming part of Letters Patent No. 123,669, dated February 13, 1872; antedated January 29, 1872.

I, GEORGE F. BLAKE, of Boston, countyof Suiolk, Commonwealth of Massachusetts, have invented an Improved Valve for Steam-Engines, of which the following is a specication:

Nature and Object of Intention.

My invention relates to the form of valve known as the cylindrical slide-valve, and has for its object the prevention of leakage between the ports when the vvalve shall have become worn by use. The cylindrical slide-valve is usually formed of a number of pistons con- A nected by a cylindrical center piece of less diameter, the pistons being of the right Width of face and placed the proper distance apart 'to form-the valve.

My improvement consists in casting the longitudinal bridges a a across the space between the piston s and turning the said bridges -lush with periphery of the pistons. A sufficient number of these bridges are so arranged f between the pistons that in whatever position lcylindrical slide-valve, when constructed and operated substantially as and for the purpose mentioned.

The above specification signed and Witnessed at Washington this 10th day of June, A. D. 1871.

GEO. F. BLAKE.

Witnesses:

GHAs. F. STANsBURY, E. R. STANsBURY. 

